When Christopher Nolan’s latest project was announced to be a big-screen interpretation of the famous evacuation of the Allied troops from Dunkirk beach in May 1940 during World War II, it seemed like an unusual choice. His recent output has concentrated on science fiction and fantasy; between directing the Dark Knight trilogy and his subsequent involvement with the Man of Steel films, he also found time to craft two epic science fiction films in the form of Inception and Interstellar.

A war epic felt like a shift into reality. Whilst nobody could doubt his credentials, such a film would certainly rely more on realistic-looking non-CGI special effects. It’s also true that getting these effects wrong would have ruined the authenticity of his art.

In the run up to the release, the controversies and concerns trickled over the media, though they were far outweighed by the plaudits from those lucky enough to see the film in previews.

One of the biggest concerns was the casting of pop singer Harry Styles in one of the lead roles. I can confidently say that any worries about his ability to act are completely unfounded. He does an excellent job in his debut role.

The entire cast are excellent. The most well-known amongst them – Mark Rylance, Cillian Murphy, Kenneth Branagh and Tom Hardy – need no praise to confirm their ability. It is the newcomers that really shine, amongst them Fionn Whitehead and Tom Glynn-Carney. The latter is a real coup for Nolan, having only acted on stage previously and even then in small quantities. He clearly has a bright future ahead of him.

Visually, the film is stunning. Everything feels real, from the harshness of the conditions to the shock of the relentless attacks, and contributes to the most stressful and involved journey I’ve been on during a film since The Revenant. It is an ordeal from start to finish, with the stress reflecting in a small way exactly what the soldiers were going through at the time.

Nolan has made a bold but effective choice in the non-linear storytelling method utilised. It is told in three intertwining parts that slowly converge into one storyline. In ‘The Mole’, the soldiers stranded on the Dunkirk beach (Styles, Whitehead and Aneurin Barnard) have a gruelling week-long escape story as Branagh’s Commandor Bolton repeatedly tries to execute an escape route for his men. In ‘The Sea’, Rylance’s Mr Dawson takes his son Peter (Glynn-Carney) and his friend George (Barry Keoghan) across the English Channel on a leisure boat to rescue evacuees, picking up an unnamed British soldier (Murphy) along the way, in a story that spans one day. In ‘The Air’, Tom Hardy’s RAF pilot Farrier’s story takes one hour to complete as he and Pilot Officer Collins (Jack Lowden) take out enemy planes in their Spitfires. As these play out, we often see visual reminders from the other storylines that serve to anchor each one alongside the others. The stories feel inextricably linked from the start, but it’s a joy to see them play out so perfectly together.

Hans Zimmer’s score is effective in unsettling the viewer throughout. It was explained recently in a fascinating article on Business Insider. “There’s an audio illusion, if you will, in music called a ‘Shepherd Tone'”, Nolan informed them. “It’s an illusion where there’s a continuing ascension of tone. It’s a corkscrew effect. It’s always going up and up and up but it never goes outside of its range. And I wrote the Dunkirk script according to that principle. I interwove the three timelines in such a way that there’s a continual feeling of intensity. Increasing intensity. So I wanted to build the music on similar mathematical principals. So there’s a fusion of music and sound effects and picture that we’ve never been able to achieve before.”

This effect is never more evident than during the final climactic moments as the score track ‘The Oil’ plays out. It’s simply breathtaking.

Christopher Nolan has made a career out of crafting cinematic experiences that feel part of one person’s vision. Like other contemporary directors like Quentin Tarantino, Wes Anderson or Nicolas Winding Refn, they are experts in their field partly because viewers can watch their films and within seconds recognise their work. They are auteurs. That Nolan seems to be achieving this in such a wide gamut of genres is all the more remarkable.

Dunkirk is a film you have to see right now. It is the film you have to see right now.